With the development of society, every year there are increasing demands in the automotive industry on cost savings, environmental safety, reduction of raw material consumption, performance improvement, material life cycle and recycling of components. In this review, emphasis is given on ferrous and non-ferrous alloys, which are used as components, where both groups can be treated by deep cryogenic treatment (DCT). DCT has shown to increase hardness, tensile strength and wear resistance, reduce density of defects in crystal structure, improve toughness and corrosion resistance. Though, some researchers also reported results that showed no change in material properties, or even deterioration of material properties, when subjected to DCT. This additionally points out to lack of consistency and reliability of the DCT process, which is needed for its successful incorporation in automotive applications. However, to prove with certainty the resulting outcome on the material properties and knowledge about the reasons for the variation of this effect on metallic materials, further approach and testing with different variables should be conducted in the future. This review provides a synopsis of different approaches of DCT on different materials for automotive applications in order to indicate effects on the material performance during DCT.
1 September 2021 in Journal of Materials Research and Technology
In recent years the efforts to better control friction and wear have focused on surface-topography modification through surface texturing. Although a lot of effort, including experimental and analytical work, has been put into finding the optimal texturing parameters and design rules for reduced friction, optimization is still too often limited and based on a trial-and-error approach. Therefore, the aim of the present research work was to investigate the possibility of using kurtosis and skewness as the design parameters for selecting the optimal texturing pattern for contact surfaces operating under lubricated conditions. The results of this investigation performed on groove- and dimple-textured surfaces under low-load, low-sliding speed conditions confirmed the correlation between the kurtosis and skewness parameters and the coefficient of friction. For textured surfaces an increase in the kurtosis and a more negative skewness, obtained by reducing the cavity size, increasing the cavity depth and decreasing the texturing density, were found to yield a lower friction. Furthermore, kurtosis and skewness were recognized as suitable parameters for the optimization of textured surfaces.
12 December 2017 in Metallurgical and Materials Transactions A